Vapor lock resistant hydraulic fluids
A composition suitable for use as a hydraulic fluid comprises:(a) a lubricating oil preferably in an amount of from 20 to 80% by weight;(b) a minor amount of oil-soluble borate ester;(c) an amine which prevents deposition of oil-insoluble hydrolysis products of the borate ester; and optionally(d) an oil soluble orthoester of the formula: ##STR1## wherein R.sup.7, R.sup.8, R.sup.9 and R.sup.10 are specified groups.
This invention relates to hydraulic fluids and particularly to mineral oil hydraulic fluids.
In hydraulic systems for which mineral oil or certain other fluids are specified as the operative fluid problems arise due to the presence of water. This water may be present as the result of condensation or inadequate drying prior to the filling of the system or subsequently, by diffusing through worn seals or flexible hoses. In either case the vapour lock temperature of the fluid can be reduced to the boiling point of water even by the presence of very minor amounts of water, e.g. of the order of 0.5%. This constitutes a serious deficiency with particularly dangerous consequences in those systems which are brake systems or central hydraulic systems including brake systems.
According to the present invention there is provided a composition suitable for use as a hydraulic fluid which comprises:
(a) a lubricating oil, preferably in an amount of from 20 to 80% by weight based on the total weight of the composition;
(b) a minor amount of oil-soluble borate ester, preferably of the general formula: ##STR2## wherein: (i) R.sup.1, R.sup.2 and R.sup.3 are the same or different and each is an aryl group or a straight or branched chain alkyl group or alicyclic group, preferably containing from 4 to 20 carbon atoms, or is a group of the formula --(R.sup.4 O).sub.n R.sup.5 wherein each R.sup.4 is the same or different and each is an alkylene group, preferably ethylene, propylene or butylene, R.sup.5 is an alkyl group, preferably containing from 1 to 18, more preferably 1 to 4, carbon atoms, or an aryl group, and n is an integer, preferably of from 1 to 10, more preferably of from 2 to 4;
or
(ii) R.sup.1 and R.sup.2 are the same or different and as defined above and R.sup.3 is a group of the general formula: ##STR3## wherein R.sup.1 and R.sup.2 are as defined above and R.sup.6 is an alkylene group, preferably containing at least 4, more preferably from 4 to 20, carbon atoms, or is an oxyalkylene radical of the formula --R.sup.4 --OR.sup.4).sub.n wherein R.sup.4 and n are as defined above;
or
(iii) R.sup.1 is as defined above and R.sup.2 and R.sup.3 together form the group ##STR4## wherein R.sup.1 is as defined above;
(c) an amine which prevents deposition of oil-insoluble hydrolysis products of the borate ester; and optionally
(d) an oil soluble orthoester of the formula: ##STR5## wherein R.sup.7 is hydrogen or an alkyl group, preferably methyl or an aryl, alkaryl, or aralkyl group; R.sup.8, R.sup.9 and R.sup.10 are the same or different, preferably the same, and each is a straight or branched chain alkyl group, preferably containing from 4 to 20 carbon atoms, an aryl, alkaryl, or aralkyl group, or the group --(R.sup.11 --O).sub.m R.sup.12 wherein each R.sup.11 is the same or different and each is an alkylene group, preferably ethylene or propylene; R.sup.12 is an alkyl group, preferably containing from 1 to 20 carbon atoms, or an aryl, alkaryl or aralkyl group; and m is an integer of from 2 to 10.
It is required that the borate ester used in the composition of the invention should be oil-soluble and, in the case of trialkyl borates, oil solubility may be provided by selecting an ester made from straight chain alcohols containing less than 12 carbon atoms or from branched chain alcohols containing up to 24 carbon atoms. In the case of borate esters of the type derived from di- and polyoxyalkylene glycol ethers, those derived from di- and polyoxyethylene glycol ethers are generally insoluble unless at least one of the terminal ether groups is sufficient to solubilise the ester. Alternatively oil-solubility for this latter type of ester may be achieved by incorporating polyoxypropylene or higher polyoxyalkylene radicals into the molecule.
Examples of particularly useful borate esters include
tris (dipropylene glycol monomethyl ether) borate
tris (ethylene glycol monobutyl ether) borate
tris (triethylene glycol monobutyl ether) borate
tris (tripropylene glycol monomethyl ether) borate
tri n-decyl borate
tri (isotridecyl) borate
tri (2-ethyl hexyl) borate
tri (3,3-dimethyl butyl) borate
The amine used in the present invention should have a reasonably low vapour pressure consistent with providing a vapour lock temperature in excess of 120.degree. C. The amine used will also depend upon the borate ester used. A simple test for determining whether a particular amine is suitable for preventing deposition of oil-insoluble hydrolysis products of a particular borate ester consists of dissolving the amine and borate in the selected lubricating oil, (in the amounts intended in the final hydraulic fluid), sealing the resulting fluid together with 0.5% by weight of water in a clear glass ampoule and heating at 100.degree. C. for 24 hours and cooling. In this so called "ampoule" test, if the resulting solution is clear and bright then the combination is satisfactory.
Many amines have been found to be suitable, including primary, secondary and tertiary amines, especially those containing a total of at least 5 carbon atoms. Amines which have been found to be particularly useful with a wide range of borates include Primene 81 R and Primene JMT which are commercially available primary amines with two methyl groups on the alpha carbon atom.
Other amines which may be useful are Mannich bases formed by condensation of an amine and formaldehyde with a phenol previously alkylated with di or polyisobutylene; polyisobutenyl succinimides derived from di or polyamines; or amides derived from di or polyalkyl polyamines and polyisbutenyl substituted monocarboxylic acids.
The amounts of components (b), (c) and (d) (when present) may each vary over a wide range. However, it is preferred to use from 1 to 50%, more preferably from 1 to 20%, particularly from 5 to 10% by weight of the borate ester; from 1 to 50%, more preferably from 5 to 30%, particularly from 10 to 20% by weight of the orthoester; and from 0.5 to 20%, more particularly from 1 to 10%, by weight of amine, the percentages being based on the total weight of the composition.
In compositions containing orthoester, the ratio of orthoester to borate may vary, for example, from 10:1 to 1:10 by weight but in general more orthoester than borate will be used, the preferred ratio varying from 5:1 to 2:1 by weight.
The ratio of borate to amine will depend upon the nature of the two particular compounds used but it is preferred to use from 5:1 to 1:1 by weight.
The lubricating oil used as base fluid in the compositions of the invention is preferably a mineral oil but may also be a synthetic hydrocarbon oil, a synthetic carboxylic acid ester or mixture thereof, a siloxane or phosphate ester or other well known synthetic lubricant.
The invention will now be illustrated by the following Examples:
Example 1 ______________________________________
Mineral oil blend 85%
Tris(tripropylene glycol
10%
monomethyl ether)borate
tridecyl borate 3%
Primene JMT 2%
______________________________________
This composition has the following physical characteristics: Boiling point 257.degree. C., Viscosity at -40.degree. C. 1328cS, Viscosity index 218. The composition was subjected to the Markey vapour-lock test in the dry state and after contamination with varying amounts of water, with the following results:
______________________________________
Water present (wt. %)
dry 0.2% 0.5% 0.75%
Vapour lock temperature
253 238 178 140
(.degree.C.)
______________________________________
The mineral oil alone with 0.5% water had a vapour lock temperature of 101.degree. C.
Examples 2 to 32Further blends comprising various combinations of borate ester and amine in mineral oil were formulated and subjected to the Gilpin vapour-lock test. Details of these blends and of the results obtained are given in Table 1.
The base fluid used in each case was a naphthenic mineral oil having the following characteristics:
______________________________________
Viscosity 130cS at -40.degree. C., 3.5cS at 100.degree. F.
and 1.31cS at 210.degree. F.
Pour point <-70.degree. F.
Boiling Point 248.degree. C.
Flash Point (closed)
208.degree. C.
Aniline Point 76.degree. C.
______________________________________
The Gilpin vapour-lock test was conducted in a Gilpin apparatus and by the Gilpin method as described in S.A.E. Paper 710 253 entitled "Operating performance of motor vehicle braking systems as affected by fluid water content." The Gilpin vapour-lock temperature (VLT) was taken to be the temperature which corresponded with the appearance of 3 ml of bubbles.
Examples 33 to 47Gilpin vapour lock temperatures were evaluated (in the manner described above) for a range of compositions containing different combinations of borate ester and lubricating oil base fluid, Primene JMT being used as the amine component in each case. Details of these compositions and of the results obtained are given in Table 2.
Example 48 ______________________________________
Tris - (tridecyl)orthoformate
10%
Tris(dipropylene glycol monomethyl-
10%
ether)borate
Primene JMT 5%
Mineral Oil 75%
______________________________________
This blend conformed with the base oil requirements of Specification DTD 585. The Gilpin vapour-lock temperature was 177.degree. C. after heating at 100.degree. C. for 24 hours with 0.5% water in a sealed glass ampoule.
Example 49 ______________________________________
Tris(tridecyl)orthoformate
20%
Tris(dipropylene glycol monomethyl
5%
ether)borate
Primene JMT 5%
Mineral Oil 70%
______________________________________
This blend also conformed to the base oil requirements to DTD 585 Specification and the Gilpin (3 ml) wet vapour-lock temperature was 203.degree. C.
Example 50 ______________________________________
Tris(tridecyl)orthoformate
20%
Tris(dipropylene glycol monomethyl)
5%
borate
Primene JMT 3%
Mineral Oil 72%
______________________________________
This blend also conformed to the base oil requirements of the DTD 585 Specification and the Gilpin (3 ml) wet vapour-lock temperature was 206.degree. C.
Example 51 ______________________________________
Tris(tridecyl)orthoformate
20%
Tris(dipropylene glycol monomethyl
5%
ether)borate
Tris(tridecyl)borate 2%
Primene JMT 3%
Mineral Oil 70%
______________________________________
This blend conformed to the base oil requirements of the DTD 858 Specification and has a Gilpin (3 ml) wet vapour-lock temperature of 205.5.degree. C.
Examples 52 to 81Further blends containing orthoester were formulated from a range of different orthoesters and borate esters. In each case Primene JMT was used as the amine component and the base fluid was the naphthenic mineral oil used in Examples 2 to 32. Samples of these blends were subjected to the Gilpin (3 ml) vapour-lock test (i) after reaction with 0.5% water at 100.degree. C. for 24 hours and (ii) after subjection to a humidity test at a Relative Humidity (RH) of 80% and temperature of 22.degree. C. substantially as described in the FMVSS 113 Specification but extended to a 5 day period and without a reference fluid. Also, the Rubber Swell properties of the test fluids with respect to nitrile rubber were determined by measuring the increase in volume of a 2.54 cm square, 2 mm thick nitrile rubber specimen in 50 mls of fluid at 120.degree. C. for 3 days.
Details of these blends and of the results obtained are given in Table 3.
The abbreviations and commercial products referred to in Tables 1 to 3 are as follows:
______________________________________
DPM dipropylene glycol monomethyl
ether
TPM tripropylene glycol monomethyl
ether
PPG polypropylene glycol
Primene 81 R and
commercially available primary
Primene JMT amines with two methyl groups
on the alpha carbon atom
Lubrizol 894 and
commercially available poly-
Hitec E 638 isobutenyl succinimides of
(Edwin Cooper) polyalkylene polyamines.
Empilan KS 3 commercially available mixture
of triethyleneglycol mono
ethers of C.sub.9 to C.sub.11 alcohols.
Empilan KB 2 commerciall available mixture
of diethylene glycol mono
ethers of C.sub.12 to C.sub.14 alcohols.
Burning Oil a paraffinic heavy kerosene
having a flash point of 260.degree. F.,
a specific gravity of 0.82 and
viscosities at 100.degree. F. and 210.degree. F.
of 4.5cS and 1.6cS respectively.
Refrigerant Oil A
a blend of naphthenic mineral
oils having a specific gravity
of 0.892, viscosity at 100.degree. F.
of 48cS, flash point of 360.degree. F.
and a pour point of -30.degree. F.
Refrigerant Oil B
a blend of naphthenic mineral
oils having a specific gravity
of 0.983, flash point of 330.degree. F.
pour point of -30.degree. F. and
viscosities at 100.degree. F. and 210.degree. F.
of 53.4cS and 5.36cS respect-
ively.
Refrigerant Oil C
a commercially available
refrigerant oil manufactured
by British Petroleum under the
trademark ZERICE 353 and
believed to be a mixture of
alkylated benzenes.
Silicone Fluid an experimental silicone brake
fluid supplied by Union Carbide
Corporation.
______________________________________
The vapour-lock test results set out in the foregoing Examples and in Tables 1 to 3 show that fluids in accordance with the invention retain unexpectedly high vapour-lock temperatures even in the presence of water. Furthermore, the rubber swell test results set out in Table 3 show that fluids in accordance with the invention may be blended so as to provide fluids having rubber swell properties acceptable in commercial hydraulic systems.
TABLE I
__________________________________________________________________________
BORATE ESTER AMINE
Example wt. wt.
No % % GILPIN VLT (.degree.C.)
__________________________________________________________________________
2 TETRA(DPM)PYROBORATE
10
PRIMENE 81 R 2 181
3 TETRA(TPM)PYROBORATE
10
LUBRIZOL 894 20 178
4 TRIS n-BUTYL BORATE
15
2-ETHYL HEXYLAMINE
2 133
5 TETRA(PENT 2YL) 10
PRIMENE JMT 5 170
PYROBORATE
6 TRIS(DPM)METABORATE
10
PRIMENE 81R 10 186
7 TRIS(n-OCTYL) 10
PRIMENE JMT 10 155
METABORATE
8 TRIS(BUTYL MONOGLYCOL)
10
PRIMENE JMT 5 167
METABORATE
9 TRIHEXYLENE GLYCOL
10
PRIMENE JMT 2 143
BISBORATE
10 TRIS(OLEYL)BORATE
15
PRIMENE JMT 10 120
11 TRIS(m-TOLYL)BORATE
10
PRIMENE JMT 2 222
12 TRIS(p-TOLYL)BORATE
10
PRIMENE JMT 2 205
13 TRIS(o-TOLYL)BORATE
10
PRIMENE JMT 2 206
14 TRIS(p-tert.BUTYL
10
PRIMENE JMT 10 177
PHENYL)BORATE
15 TRIS(BENZYL)BORATE
10
PRIMENE JMT 5 151
16 TRIS(n-OCTYL)BORATE
15
DIHEXYLAMINE 2 139
17 TRIS(PENT 2YL) 15
PRIMENE 81R 5 144
BORATE
18 TRIS(2 NAPHTHYL) 10
PRIMENE JMT 10 218
BORATE
19 HEXYLENE GLYCOL BIS
10
PRIMENE JMT 2 167
DPM BIS BORATE
20 PPG 1200 BIS ISO-
15
PRIMENE JMT 10 138
TRIDECYL BIS BORATE
21 TRIS(OCT 2YL)BORATE
15
PRIMENE JMT 7 179
22 TRIS(ISODECYL)BORATE
15
PRIMENE JMT 10 135
23 TRIS(ISOTRIDECYL)
15
PRIMENE JMT 10 131
BORATE
24 TRIS(ISO-OCTADECYL)
20
PRIMENE JMT 20 126
BORATE
25 TRIS(3 METHYL 15
TRIOCTYLAMINE 20 154
1 BUTYL)BORATE
26 TRIS(3 METHYL PENT
15
PRIMENE JMT 5 171
3YL)BORATE
27 TRIS(2 METHYL 15
PRIMENE JMT 5 171
CYCLOHEXYL)BORATE
28 TRIS(BUTYL MONO- 15
DIALLYLAMINE 5 169
GLYCOL)BORATE
29 TRIS(BUTYL TRIGLYCOL)
15
n-HEXYLAMINE 2 184
BORATE
30 TRIS(HEXYL-DIGLYCOL)
15
PRIMENE 81R 2 145
31 TRIS(DPM)BORATE 10
HITEC E 638 20 186
32 TRIS(TPM)BORATE 10
PRIMENE JMT 10 181
__________________________________________________________________________
TABLE 2
__________________________________________________________________________
BORATE ESTER
Example wt
PRIMENE GILPIN
No % JMT (wt %)
BASE FLUID VLT (.degree.C.)
__________________________________________________________________________
33 TRIS(n-BUTYL)BORATE
15
5 BURNING OIL 142
34 TRIS HEXYLENE GLYCOL
10
5 BURNING OIL 157
BIS BORATE
35 TRIS (BUTOXYETHOXY
15
5 BURNING OIL 166
PROPYL)BORATE
36 TRIS(2 METHYL CYCLO-
15
5 DI(ISO-OCTYL) 220
HEXYL)BORATE ADIPATE
37 TRIS(BUTYL MONO 15
2 REFRIGERANT OIL A
185
GLYCOL)BORATE
38 TRIS(3 METHYL 1 15
5 REFRIGERANT OIL B
153
BUTYL)BORATE
39 TRIS(o-BUTYL) 15
5 REFRIGERANT OIL C
236
BORATE/TRIS(O-TOLYL)
BORATE
40 TRIS(n-BUTYL)BORATE
15
5 SILICONE FLUID 133
41 TRIS(BUTYL MONO- 15
5 SILICONE FLUID 188
GLYCOL)BORATE
42 TRIS(3 METHYL 1 BUTYL)
15
5 PENTAERYTHRITOL-
180
BORATE HEPTANOATE
43 TRIS(o-TOLYL)BORATE
10
5 TRIMETHYLOL PROPANE
256
44 TRIS(BUTYL TRIGLYCOL)
15
5 DI (TRIDECYL) 223
BORATE DODECANE DIOATE
45 TRIS(DPM)BORATE 10
5 DI(2-ETHYLHEXYL)
218
DODECANE DIOATE
46 TRIS(PHENYL GLYCOL ETHER)
10
2 TRIBUTYL PHOSPHATE
205
BORATE
47 TRIS(EMPILAN KS 3)
10
2 TRI BUTYL PHOSPHATE
195
BORATE
__________________________________________________________________________
TABLE 3
__________________________________________________________________________
ORTHOESTER BORATE ESTER
Example wt wt
No Name % NAME %
__________________________________________________________________________
52 TRIS(BUTYL)ORTHOFORMATE
25 TRIS(n-DECYL)ORTHOBORATE
12
53 TRIS(BUTYL)ORTHOFORMATE
15 TRIS(n-OCTYL)ORTHOBORATE
5
54 TRIS(2 ETHYL HEXYL)
28 TRIS(n-BUTYL)ORTHOBORATE
7
ORTHOFORMATE
55 TRIS(2 ETHYL HEXYL)
25 TRIS(TRIDECYL)ORTHOBORATE
20
ORTHOFORMATE
56 TRIS(BUTYL TRIGLYCOL)
30 TRIS(ISO DECYL)ORTHOBORATE
11
ORTHOFORMATE
57 TRIS(DOWANOL DPM) 15 TRIS(METHYL BUTYL) 13
ORTHOFORMATE ORTHOBORATE
58 TRIS(TRIDECYL) 30 TRIS(PENT-2-YL) 15
ORTHOFORMATE ORTHOBORATE
59 TRIS(TRIDECYL) 15 TRIS(2-OCTYL)ORTHOBORATE
13
ORTHOACETATE
60 TRIS(TRIDECYL) 25 TRIS(OLEYL)ORTHOBORATE
15
ORTHOFORMATE
61 TRIS(OLEYL) ORTHOFORMATE
15 TRIS(p-TOLYL)ORTHOBORATE
3
62 TRIS(DPM)ORTHOACETATE
10 TRIS(BUTYL MONOGLYCOL)
6
63 TRIS(BUTYL TRIGLYCOL)
30 TRIS(BUTYL TRIGLYCOL)
17
ORTHOFORMATE ORTHOBORATE
64 TRIS(DPM)ORTHOFORMATE
15 TRIS(HEXYL DIGLYCOL)
4
ORTHOBORATE
65 TRIS(OLEYL)ORTHOFORMATE
20 TRIS(DPM)ORTHOBORATE
5
66 TRIS(BENZYL)ORTHOFORMATE
20 TRIS(BUTYL MONOGLYCOL)
5
ORTHOBORATE
67 TRIS(ISO OCTADECYL)
25 TETRA(TPM)PYBORATE 4
ORTHOFORMATE
68 TRIS(DPM)ORTHOACETATE
17 TRIS(DPM)METABORATE
4
69 TRIS(ALLYL)ORTHOFORMATE
19 TRIS(BENZYL)ORTHOBORATE
7
70 TRIS(BUTYL MONOGLYCOL)
25 TRIS(METHYL CYCLOHEXYL)
10
ORTHOACETATE ORTHOBORATE
71 TRIS(TRIDECYL)ORTHO-
15 TRIS(TPM)ORTHOBORATE
2
FORMATE
72 TRIS(BUTYL MONOGLYCOL)
30 TETRA(DPM)PYROBORATE
3
ORTHOACETATE
73 TRIS(ISO OCTADECYL)
27 HEXAMETHYLENE GLYCOL BIS
9
ORTHOFORMATE DPM. BIS BORATE
74 TRIS(2 ETHYL HEXYL)
22 TETRA(BUTYL MONOGLYCOL)
5
ORTHOFORMATE PYROBORATE
75 TRIS(EMPILAN KB2) 14 TRIS(EMPILAN KB2) 5
ORTHOFORMATE ORTHOBORATE
76 TRIS(DPM)ORTHOACETATE
23 TRIS(ISOOCTADECYL) 6
ORTHOBORATE
77 TRIS(BUTYL MONOGLYCOL)
21 TRIS(p-tert.BUTYL 8
ORTHOACETATE PHENYL)ORTHOBORATE
78 TRIS(BUTYL TRIGLYCOL)
24 TRIS(2 NAPHTHYL) 9
ORTHOFORMATE ORTHOBORATE
79 TRIS(DPM)ORTHOFORMATE
14 PPG 1200 BIS TRIDECYL
3
BIS BORATE
80 TRIS(3 METHYL PENTYL)
15 TRIS(TPM)ORTHOBORATE
4
ORTHOFORMATE
81 TRIS(TRIDECYL)ORTHO-
15 TRIS(DPM)ORTHOBORATE
2
VALERATE
__________________________________________________________________________
GILPIN VLT
GILPIN VLT AFTER 5 DAY
NITRILE RUBBER
AFTER REACTION
HUMIDITY TEST
Example
AMINE VOLUME SWELL (%)
WITH 0.5% WATER
80% RH 22.degree. C.
No NAME wt %
(3 days at 120.degree. C.)
(.degree.C.)
(.degree.C.)
__________________________________________________________________________
52 PRIMENE JMT
5 1.55 144 128
53 PRIMENE JMT
6 3.5 134 148
54 PRIMENE 81R
2 0.7 161 154
55 PRIMENE JMT
10 0.9 198 203
56 PRIMENE JMT
10 12.4 195 138
57 PRIMENE JMT
10 5.1 172 130
58 PRIMENE JMT
12 -1.6 164 120
59 PRIMENE JMT
8 3.4 184 115
60 PRIMENE JMT
10 3.5 185 133
61 PRIMENE JMT
3 11.3 -- 221
62 PRIMENE JMT
2 6.1 152 120
63 PRIMENE 81R
3 19.8 168 137
64 PRIMENE UMT
1 8.8 174 211
65 PRIMENE JMT
3 2.5 129 156
66 PRIMENE JMT
5 32.9 199 196
67 PRIMENE JMT
2 -0.2 154 249
68 PRIMENE JMT
10 13.3 171 175
69 PRIMENE JMT
4 17.1 120 110
70 PRIMENE JMT
5 7.8 193 155
71 PRIMENE JMT
2 0.3 147 242
72 PRIMENE JMT
6 9.7 197 202
73 PRIMENE JMT
2 0.2 214 218
74 PRIMENE JMT
5 4.5 178 144
75 PRIMENE JMT
3 2.9 126 133
76 PRIMENE JMT
3 8.0 179 207
77 PRIMENE JMT
8 23.1 205 149
78 PRIMENE JMT
9 35.6 204 172
79 PRIMENE JMT
5 6.0 166 212
80 PRIMENE JMT
3 11.3 112.5 123
81 PRIMENE JMT
2 1.9 127* 149
__________________________________________________________________________
*With 0.25% Water
Claims
1. A composition of matter suitable for use as a hydraulic fluid which comprises
- (a) at least 20%, by weight, of a lubricating oil which is a member selected from the group consisting of a mineral oil, a synthetic hydrocarbon oil, a synthetic carboxylic acid ester, a siloxane or a phosphate ester;
- (b) 1 to 50%, by weight, of oil-soluble borate ester which is a compound, or mixture of compounds, having the formula: ##STR6## wherein: (i) R.sup.1, R.sup.2 and R.sup.3 are the same or different and each is an aryl group or a straight or branched chain alkyl group or alicyclic group containing from 4 to 20 carbon atoms, or is a group of the formula --R.sup.4 O).sub.n R.sup.5 wherein each R.sup.4 is the same or different and each is an alkylene group selected from ethylene, propylene or butylene, R.sup.5 is an alkyl group containing from 1 to 18 carbon atoms, or an aryl group, and n is an integer, from 1 to 10; or
- (ii) R.sup.1 and R.sup.2 are the same or different and as defined above and R.sup.3 is a group of the general formula: ##STR7## wherein R.sup.1 and R.sup.2 are as defined above and R.sup.6 is an alkylene group containing from 4 to 20 carbon atoms, or is an oxyalkylene radical of the formula --R.sup.4 --OR.sup.4).sub.n wherein R.sup.4 and n are as defined above; or
- (iii) R.sup.1 is as defined above and R.sup.2 and R.sup.3 together form the group ##STR8## wherein R.sub.1 is as defined above; (c) 0.5 to 20%, by weight, of an amine which prevents deposition of oil insoluble hydrolysis products of the borate ester; and
- (d) 1 to 50%, by weight, of an oil soluble orthoester of the formula: ##STR9## wherein R.sup.7 is hydrogen or lower alkyl; R.sup.8, R.sup.9 and R.sup.10 are the same or different and each is a straight or branched chain alkyl containing from 4 to 20 carbon atoms, benzyl or the group --(R.sup.11 --O).sub.m --R.sup.12 where R.sup.11 is a lower alkylene group and R.sup.12 is an alkyl group containing 1 to 20 carbon atoms; and m is an integer from 2 to 10.
2. A composition as claimed in claim 1 wherein R.sup.7 is a hydrogen atom or a methyl group.
3. A composition as claimed in claim 1 which contains from 5 to 30% by weight of orthoester based on the total weight of the composition.
4. A composition as claimed in claim 1 wherein the ratio of orthoester to borate ester is in the range from 5:1 to 2:1 by weight.
5. A composition as claimed in claim 1 containing from 1 to 20% by weight of borate ester based on the total weight of the composition.
6. A composition as claimed in claim 1 containing from 1 to 10% by weight of amine based on the total weight of the composition.
7. A composition as claimed in claim 1 wherein the ratio of borate ester to amine is from 5:1 to 1:1 by weight.
| 2996451 | August 1961 | Irish et al. |
| 3080412 | March 1963 | Young |
| 3125528 | March 1964 | Kay et al. |
| 3200074 | August 1965 | Knowles et al. |
| 3711411 | January 1973 | Sawyer et al. |
| 3903006 | September 1975 | Elliott et al. |
Type: Grant
Filed: Mar 18, 1983
Date of Patent: May 22, 1984
Inventors: Herbert F. Askew (Kiln Ride, Wokingham, Berkshire), Colin J. Harrington (Wokingham, Berkshire), Terry J. P. Bridgwater (Winnersh, Berkshire)
Primary Examiner: John E. Kittle
Assistant Examiner: Robert A. Wax
Application Number: 6/476,561
International Classification: C10M 126; C10M 154;
